diff --git a/xctool/xctool-tests/OTestQueryTests.m b/xctool/xctool-tests/OTestQueryTests.m
index a687c3ee7..32add472f 100644
--- a/xctool/xctool-tests/OTestQueryTests.m
+++ b/xctool/xctool-tests/OTestQueryTests.m
@@ -84,4 +84,16 @@ - (void)testQueryFailsWhenDYLDRejectsBundle_iOS
   assertThat(error, containsString(@"no suitable image found."));
 }
 
+- (void)testIOSAppTestQueryFailsWhenTestHostExecutableIsMissing
+{
+  NSString *error = nil;
+  NSString *latestSDK = GetAvailableSDKsAndAliases()[@"iphonesimulator"];
+  NSArray *classes = OTestQueryTestCasesInIOSBundleWithTestHost(TEST_DATA @"otest-query-tests-ios-test-bundle/TestProject-LibraryTests.octest",
+                                                                @"/path/to/executable/that/does/not/exist",
+                                                                latestSDK,
+                                                                &error);
+  assertThat(classes, equalTo(nil));
+  assertThat(error, containsString(@"The test host executable is missing: '/path/to/executable/that/does/not/exist'"));
+}
+
 @end
diff --git a/xctool/xctool/OTestQuery.m b/xctool/xctool/OTestQuery.m
index 720653f83..c52654cea 100644
--- a/xctool/xctool/OTestQuery.m
+++ b/xctool/xctool/OTestQuery.m
@@ -75,6 +75,11 @@
 {
   NSCAssert([sdk hasPrefix:@"iphonesimulator"], @"Only iphonesimulator SDKs are supported.");
 
+  if (![[NSFileManager defaultManager] isExecutableFileAtPath:testHostExecutablePath]) {
+    *error = [NSString stringWithFormat:@"The test host executable is missing: '%@'", testHostExecutablePath];
+    return nil;
+  }
+
   NSString *version = [sdk stringByReplacingOccurrencesOfString:@"iphonesimulator" withString:@""];
   DTiPhoneSimulatorSystemRoot *systemRoot = [DTiPhoneSimulatorSystemRoot rootWithSDKVersion:version];
   NSCAssert(systemRoot != nil, @"Cannot get systemRoot");